3. The genetic code is commaless, which means that no codon is reserved for punctuations. It means that after one amino acid is coded, the second amino acid will be automatically, coded by the next three letters and that no letters are wasted as the punctuation marks (Fig.
Summer solstice is the first day of summer - it's usually between June 20th and June 23rd. In 2016, the summer solstice takes place on June 20th. We know it's summer because the earth's axis tilts toward the sun from June to September - this means warmer weather and longer days.
Because the summer solstice occurs when the North Pole is tilted most towards the sun, the sun reaches its highest point in the sky on that day, which usually occurs around June 21 each year. From now on, days will only get shorter as we travel toward the winter solstice on Dec. 21.